Amalgamator for separating noble metals



Sept. 14, 1937. H. ovoRzsAK ET AL AMALGAMATOR F OR SEPARATING NOBLEMETALS Filed Nov. 30, 1935 INVENTORS DvoRZS/iK KACHELMANN Patented Sept.14, 1937 "UNITED STATES AMALGAMATOR FOR SEPARATING NOBLE METALS HeinrichDvorzsak, Kremnice, and Alexander Valentnyi, Vyhne, Czechoslovakia, andKarl Kachelmann, Ujpest, Hungary Application November 30, 1935, SerialNo. 52,428 In Czechoslovakia, December 3, 1934 3 Claims.

The invention relates to a type of apparatus called amalgamators,rendering possible the separation of such noble metals present in freelyaccessible condition in ores as will form amalgam with mercury, the oresbeing charged into the amalgamator in the form of slime suitablyprepared for treatment.

An embodiment of the invention is illustrated by Way of example on thedrawing.

Figs. 1 and 2 are a longitudinal and a crosssection, respectively, ofthe amalgamator, Figs. 3 and 4 of the amalgam plates, Fig. 5 shows thearrangement of the shower-spray in the amalgam collector.

The machine consists of a closed casing, in which a system of amalgamplates l8, fixed in a position parallel to the shaft on two discs I4, l6rotates around a. horizontal shaft. l3. These amalgam plates aresilver-plated copper sheets coated with mercury.

The casing consists of a cylinder I, of a lateral wall 2 with charginghopper and a second lateral wall 3 with removable lid. The casing isfitted below with a drain opening 5 capable of being closed, which isused for the discharge of the contents of the machine after the latterhas been shut down. On the side opposite to that on which the drainopening is provided the casing is along its whole width constructed inthe shape of a box, and serves here as an amalgam collector 6 whichlikewise is capable of being completely closed. In this chamber ashower-spray 1 is installed through which clean Water is introducedunder pressure, in order to prevent, by its continuous flow, anysettling of the slime in this chamber. The extension of the amalgamcollector is constructed along its whole width as a discharge gutter ofthe slime. The charging hopper provided on the lateral wall 2 isconnected with the,

upper chamber of the casing by a pipe elbow 8a, in order to enable theapparatus to be vented and in order to lead ofi any overflow. On thislateral wall a bracket for accommodating a bearing, a stuffing-box, anopening through which the slime fiows over into the plate system, a pipebranch 9 through which clean water is flowing under pressure, in orderto seal the casing against the hopper, a second pipe branch H], forenabling the stufiing-box to be sealed by means of water under pressure,and the opening H for the admission of the mercury are provided. Thelower part of the lateral wall is designed in the manner of a sole-plateand serves for fixing the machine to the foundation.

On the lower half of the second lateral wall 3 there are providedlikewise a bracket for accommodating the second bearing, a stuffing-box,and a pipe branch l2 serving for the admission of the water underpressure into the stuifing-box. Below, the lateral wall is likewiseshaped as a soleplate. The upper, removable half of the lateral wall 4(also called li-d) serves for giving access to the plate system and forenabling the plates to be removed or inserted through this opening. Thelid 4 and the blind flanges 5 and 6 are fixed to the flanges by means ofbolts, but can also be made inaccessible, in such amanner that it ispossible to keep them completely locked off in a suitable manner. 1 Theshaft l3 runs over the two stufiingboxes and is supported in the bearingsupported on the brackets. Driving takes place by means of a pair ofgear wheels through a pulley.

The main part of the amalgamator is the system of amalgam plates whichis keyed on the shaft and is composed of the following parts: of a discM; the hubof which is designed as an inlet opening, of a spider 15 witharms made of round bars, of a disc Hi consisting of two parts, of anumber of concentrically arranged bars ll of steel and of the amalgamplates [8. The bars are fixed on one end to the disc and on the otherend to the arms of the spider, the external bars being moreover alsofixed on the disc consisting of two parts. The bars are slotted on bothsides for receiving the plates. After the plates have been inserted intothe corresponding slots the plates are forming a number of octagonaltubes or prisms; The internal amalgam plates are shorter than the barsand are alternately leaning against the lateral discs, so that openingsare formed between the discs and the plates, through which openings theslime fiows from one prism into the other. The external plates are ofthe same length as the bars and are fitted with separate dischargeopenings, through which the slime leaves the amalgamator. The plates arefixed in their positions by a bolt l9 and rubber cushions 20. The discl6 consisting of two parts is fixed in the middle to the spider l5 andon its external periphery to the bars. Stirring vanes 2| are provided onthe external side of the discs and stirring angles 22 on the externalbars. The stirring vanes and angles serve for stirring the slime inorder to prevent any settling.

The machine operates in the following manner:

The slime flows through the hopper into the apparatus and fills theWhole of the casing, and leaves the machine in due course through thedischarge gutter. The amalgam plates are dur ing all the time immersedinto the slime in their entire extent, without coming into contact withthe atmospheric air. The larger grains of noble metal will fall to theground in the first tube already and become amalgamated. The more 5 finethe condition into which the ores are brought, the later will the grainsof noble metal come into contact with the plates, and for this reason itis necessary to pass the slime through tubes or prisms the diameters ofwhich are constantly increasing in order to diminish the flow velocityof the slime, so as to give occasion even to the smallest particles tocome into contact likewise with the plates. The fact that the prisms areof octagonal shape and are rotating increases the possibility ofcontact. The slime leaving the amalgam plates, which now alreadycontains only the sizes of grain not sufficiently opened up or thosebound, passes through the discharge opening into the flotation plant,lye plant etc. for the purpose of being subjected to further treatment;

As it is only a certain quantity of ore (not exceeding 20%) that themercury is able to amalgamate, it is necessary to effect a supplementaryfeeding of mercury through the opening ll.

Any particles of amalgam or mercury which may possibly become detachedfrom the plates will drop into the casing and will be passed by the flowof the slime and by the trailing action of the stirring devices into theamalgam col- 0 lector. In order to remove the amalgam adhering to theplates the lid 4 and the disc I6 are removed, whereby the plates willbecome ready for being removed from the apparatus.

The amalgamator according to the invention 35 possesses the greatadvantage, as compared to the known types of amalgamators, that owing tothe gradually diminishing flow speed, the particles of noble metalcontained in the slime have occasion, during a relatively considerablelength of 40 time, for coming into contact with a large amalgam surface,i. .e. for becoming amalgamated. This method of operation ensures thefurther advantage that the fine and fiat particles of noble metal willalso be retained by adhesion on the plates, whereby the yield percentagewill be substantially increased.

Another advantage of the apparatus consists in the fact that the amalgamcollector is built into the machine itself whereby the loss in metal andmercury is substantially diminished.

Finally we would mention the advantage, the importance of which shouldnot be underrated, that the closed arrangement renders access to thevaluable amalgam impossible for unauthorized persons, i. e. prevents anystealing of gold.

What weclaim is:

1. An amalgamator for treating materials containing precious metals,comprising a closed rotatably mounted drum, and a plurality of platesalternately secured to the opposite ends of the drum with the free endsof the plates overlapping each other and forming therewith a Zigzag pathof flow of the material, said plates forming annular members concentricwith the drum whereby the flow of the material extends axially of theaxis of the drum.

2. An amalgamator according to claim 1 in which a lid is provided in-thedrum and the plates are removably secured so that said plates may beremoved from the drum through an opening covered by the lid.

3. An amalgamator for treating materials containing precious metals,comprising a. closed r0- tatably mounted drum; and a plurality of platesalternately secured to the opposite ends of the drum with the free endsof the plates overlapping each otherand forming therewith a zigzag pathof flow of the material, said plates forming annular polygonal memberswithin thedrum Whereby the flow of the material extends axially of theaxis of the drum.

HEINRICH DVORZSAK. ALEXANDER VALENTENYI. KARL KACHELMANN.

